Devil’s Bargain

A trope of sci-fi movies these days, from Snowpiercer to Geostorm, is that our failure to tackle climate change will eventually force us to deploy an arsenal of unproven technologies to save the planet. Think sun-deflecting space mirrors or chemically altered clouds. And because these are sci-fi movies, it’s assumed that these grand experiments in geoengineering will go horribly wrong.

The fiction, new evidence suggests, may be much closer to reality than we thought.

When most people hear “climate change,” they think of greenhouse gases overheating the planet. But there’s another product of industry changing the climate that has received scant public attention: aerosols. They’re microscopic particles of pollution that, on balance, reflect sunlight back to space and help cool the planet down, providing a crucial counterweight to greenhouse-powered global warming.

An effort to co-opt this natural cooling ability of aerosols has long been considered a potential last-ditch, desperate shot at slowing down global warming. The promise of planet-cooling technology has also been touted by techno-optimists, Silicon Valley types and politicians who aren’t keen on the government doing anything to curb emissions. “Geoengineering holds forth the promise of addressing global warming concerns for just a few billion dollars a year,” wrote Newt Gingrich in an attack on proposed cap-and-trade legislation back in 2008.

But there’s a catch. Our surplus of aerosols is a huge problem for those of us who like to breathe air. At high concentrations, these tiny particles are one of the deadliest substances in existence, burrowing deep into our bodies where they can damage hearts and lungs.